[PATCH] lib/vsprintf: add __putchar()
From: Yury Norov
Date: Fri Aug 27 2021 - 13:12:03 EST
There are 26 occurrences of the code snippet like this in the file :
if (buf < end)
*buf = separator;
++buf;
This patch adds a helper function __putchar() to replace opencoding.
It adds a lot to readability, and also saves 43 bytes of text on x86.
Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
lib/vsprintf.c | 174 +++++++++++++++++--------------------------------
1 file changed, 59 insertions(+), 115 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 134216c45980..58a985686c08 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -53,6 +53,14 @@
#include <linux/string_helpers.h>
#include "kstrtox.h"
+static inline char *__putchar(char *buf, const char *end, char c)
+{
+ if (buf < end)
+ *buf = c;
+
+ return buf + 1;
+}
+
static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
char **endp, unsigned int base)
{
@@ -509,59 +517,38 @@ char *number(char *buf, char *end, unsigned long long num,
/* leading space padding */
field_width -= precision;
if (!(spec.flags & (ZEROPAD | LEFT))) {
- while (--field_width >= 0) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
+ while (--field_width >= 0)
+ buf = __putchar(buf, end, ' ');
}
/* sign */
- if (sign) {
- if (buf < end)
- *buf = sign;
- ++buf;
- }
+ if (sign)
+ buf = __putchar(buf, end, sign);
+
/* "0x" / "0" prefix */
if (need_pfx) {
- if (spec.base == 16 || !is_zero) {
- if (buf < end)
- *buf = '0';
- ++buf;
- }
- if (spec.base == 16) {
- if (buf < end)
- *buf = ('X' | locase);
- ++buf;
- }
+ if (spec.base == 16 || !is_zero)
+ buf = __putchar(buf, end, '0');
+ if (spec.base == 16)
+ buf = __putchar(buf, end, 'X' | locase);
}
/* zero or space padding */
if (!(spec.flags & LEFT)) {
char c = ' ' + (spec.flags & ZEROPAD);
- while (--field_width >= 0) {
- if (buf < end)
- *buf = c;
- ++buf;
- }
+ while (--field_width >= 0)
+ buf = __putchar(buf, end, c);
}
/* hmm even more zero padding? */
- while (i <= --precision) {
- if (buf < end)
- *buf = '0';
- ++buf;
- }
+ while (i <= --precision)
+ buf = __putchar(buf, end, '0');
+
/* actual digits of result */
- while (--i >= 0) {
- if (buf < end)
- *buf = tmp[i];
- ++buf;
- }
+ while (--i >= 0)
+ buf = __putchar(buf, end, tmp[i]);
+
/* trailing space padding */
- while (--field_width >= 0) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
+ while (--field_width >= 0)
+ buf = __putchar(buf, end, ' ');
return buf;
}
@@ -619,11 +606,9 @@ char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
move_right(buf - n, end, n, spaces);
return buf + spaces;
}
- while (spaces--) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
+ while (spaces--)
+ buf = __putchar(buf, end, ' ');
+
return buf;
}
@@ -638,9 +623,7 @@ static char *string_nocheck(char *buf, char *end, const char *s,
char c = *s++;
if (!c)
break;
- if (buf < end)
- *buf = c;
- ++buf;
+ buf = __putchar(buf, end, c);
++len;
}
return widen_string(buf, len, end, spec);
@@ -968,11 +951,9 @@ char *bdev_name(char *buf, char *end, struct block_device *bdev,
hd = bdev->bd_disk;
buf = string(buf, end, hd->disk_name, spec);
if (bdev->bd_partno) {
- if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
- if (buf < end)
- *buf = 'p';
- buf++;
- }
+ if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
+ buf = __putchar(buf, end, 'p');
+
buf = number(buf, end, bdev->bd_partno, spec);
}
return buf;
@@ -1175,18 +1156,10 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
len = min_t(int, spec.field_width, 64);
for (i = 0; i < len; ++i) {
- if (buf < end)
- *buf = hex_asc_hi(addr[i]);
- ++buf;
- if (buf < end)
- *buf = hex_asc_lo(addr[i]);
- ++buf;
-
- if (separator && i != len - 1) {
- if (buf < end)
- *buf = separator;
- ++buf;
- }
+ buf = __putchar(buf, end, hex_asc_hi(addr[i]));
+ buf = __putchar(buf, end, hex_asc_lo(addr[i]));
+ if (separator && i != len - 1)
+ buf = __putchar(buf, end, separator);
}
return buf;
@@ -1221,11 +1194,9 @@ char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
bit = i % BITS_PER_LONG;
val = (bitmap[word] >> bit) & chunkmask;
- if (!first) {
- if (buf < end)
- *buf = ',';
- buf++;
- }
+ if (!first)
+ buf = __putchar(buf, end, ',');
+
first = false;
spec.field_width = DIV_ROUND_UP(chunksz, 4);
@@ -1248,20 +1219,17 @@ char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
return buf;
for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
- if (!first) {
- if (buf < end)
- *buf = ',';
- buf++;
- }
+ if (!first)
+ buf = __putchar(buf, end, ',');
+
first = false;
buf = number(buf, end, rbot, default_dec_spec);
if (rtop == rbot + 1)
continue;
- if (buf < end)
- *buf = '-';
- buf = number(buf + 1, end, rtop - 1, default_dec_spec);
+ buf = __putchar(buf, end, '-');
+ buf = number(buf, end, rtop - 1, default_dec_spec);
}
return buf;
}
@@ -1822,14 +1790,9 @@ char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
int mon = tm->tm_mon + (r ? 0 : 1);
buf = number(buf, end, year, default_dec04_spec);
- if (buf < end)
- *buf = '-';
- buf++;
-
+ buf = __putchar(buf, end, '-');
buf = number(buf, end, mon, default_dec02_spec);
- if (buf < end)
- *buf = '-';
- buf++;
+ buf = __putchar(buf, end, '-');
return number(buf, end, tm->tm_mday, default_dec02_spec);
}
@@ -1838,14 +1801,9 @@ static noinline_for_stack
char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
{
buf = number(buf, end, tm->tm_hour, default_dec02_spec);
- if (buf < end)
- *buf = ':';
- buf++;
-
+ buf = __putchar(buf, end, ':');
buf = number(buf, end, tm->tm_min, default_dec02_spec);
- if (buf < end)
- *buf = ':';
- buf++;
+ buf = __putchar(buf, end, ':');
return number(buf, end, tm->tm_sec, default_dec02_spec);
}
@@ -1889,11 +1847,8 @@ char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
if (have_d)
buf = date_str(buf, end, tm, raw);
- if (have_d && have_t) {
- if (buf < end)
- *buf = iso8601_separator ? 'T' : ' ';
- buf++;
- }
+ if (have_d && have_t)
+ buf = __putchar(buf, end, iso8601_separator ? 'T' : ' ');
if (have_t)
buf = time_str(buf, end, tm, raw);
@@ -1972,11 +1927,8 @@ char *format_flags(char *buf, char *end, unsigned long flags,
buf = string(buf, end, names->name, default_str_spec);
flags &= ~mask;
- if (flags) {
- if (buf < end)
- *buf = '|';
- buf++;
- }
+ if (flags)
+ buf = __putchar(buf, end, '|');
}
if (flags)
@@ -2026,16 +1978,11 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
continue;
/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
- if (append) {
- if (buf < end)
- *buf = '|';
- buf++;
- }
+ if (append)
+ buf = __putchar(buf, end, '|');
buf = string(buf, end, pff[i].name, default_str_spec);
- if (buf < end)
- *buf = '=';
- buf++;
+ buf = __putchar(buf, end, '=');
buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
*pff[i].spec);
@@ -2125,11 +2072,8 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
int precision;
- if (pass) {
- if (buf < end)
- *buf = ':';
- buf++;
- }
+ if (pass)
+ buf = __putchar(buf, end, ':');
switch (*fmt) {
case 'f': /* full_name */
--
2.30.2